Personal jewellery, such as rings, necklaces, bracelets, etc., are expensive items which can be of great value to their owners. Items of jewellery typically comprise a precious stone in a setting, which itself is typically composed of a precious metal, such as gold, platinum or silver. Both the gemstone and the setting may be extremely expensive individually, but the combination may be crafted together by a skilled smith to produce a work of extreme value. Furthermore, as items of jewellery are often given as gifts to commemorate special occasions, such as birthdays, anniversaries, engagements and weddings, they are frequently of significant sentimental value to the wearer.
A common problem experienced by wearers and owners of items of jewellery is that the precious gem stone-becomes loose in its setting and may become dislodged. This may occur due to the age of the jewellery or if it is subjected to a jolt or shock, for example if a ring falls from the wearer's finger onto the ground. Typically the gem stone will ‘work loose’ over an extended period of time, following such a jolt or shock. The wearer of the jewellery is generally unaware that the precious stone has become dislodged from its setting and consequently doesn't realise that there is a problem. Unfortunately the result all too often is that the precious stone eventually works free of the setting and is lost, causing both financial and often personal loss for the wearer. Although the owner may replace the stone (often at significant expense) with a similar gem, the stone may have held significant sentimental value and consequently can never truly be replaced.
The present invention addresses the problem of assessing whether a precious stone has become loose or dislodged from its jewellery setting. In particular, it provides a means for assessing whether the integrity of grip of a stone is intact in a jewellery setting having plural gripping claws to grip said stone. The method relies on measuring heat transfer (i.e. conductivity of heat) from the stone to the gripping claws. Good heat transfer will be expected for good claw integrity, whereas poor heat transfer provides an indication that the stone has come loose from the claw, and hence is loose in the overall setting.
The method is relatively straightforward to implement at low cost, and is non-invasive. That is to say, it may be conducted without manual prodding or tinkering with the setting, which may in itself result in damage if not conducted with great care.
The method also provides the advantage that it may be used to identify a single poor stone-claw gripping relationship, even in a jewellery setting (e.g. a ring) where the overall integrity (as a result of all the other claw grips) is acceptable. It therefore provides a way of pre-emptively predicting total (i.e. catastrophic) failure setting integrity before it happens.